This proposal is a Coordinating Center (CC) response to the RFA on Dietary Patterns and Blood Pressure. The CC will be located at the Kaiser Permanente Center for Health Research (CHR), with consultation from the Oregon Health Sciences University and a subcontract for food composition analyses to Virginia Polytechnic Institute. The CHR and the investigators have extensive experience in the conduct of clinical trials, hypertension research, feeding studies, food analysis, and the handling and analysis of large databases. The applicants also have experience as a coordinating center, and the CHR is structured to optimally support such an institution. We propose a three-armed trial, preceded by a 4-week run-in, "typical American" diet. The "typical American" diet would be continued as the control diet during the intervention phase of the study. The two comparisons would involve high mineral (K, Mg, Ca) and low fat-high fiber diets. We also propose that non-perishable foods be prepared in a central kitchen, frozen, and shipped to clinical centers to maximize uniformity of diets and minimize quality control problems. Finally, we propose a mechanism for reducing variance in blood pressure by taking advantage of the daily visits of trial subjects. The proposed design has considerably greater power for detecting changes in blood pressure than does the model suggested in the RFA. The combination of expertise and experience of the applicants makes the CHR and its affiliated scientists an ideal group for serving as coordinating center for this trial.